I had a Blackberry Curve for about six weeks -- I hated it!
Hated that the dialing keypad was a tiny, tiny corner of the qwerty keyboard.
Hated that the phone would recognize the storage chip, but would not use the chip for saving photos. Hated the tiny screen.
An iphone user pointed out that I could get an unlocked phone and transfer my TMobile SIM card. two days later I had an iPhone -- and I LOVE it!

went from a Blackberry Tour 9630 on US Cellular, to an old one we had to save some money. It was a Moto VE20. Then decided, screw that... I needed to have a smart phone and wanted my music with me, so I switched us to AT&T and got myself a 3GS and my wife a 3G.

The last phone I used (and I still have it) is the Nokia 5800 XM. My work forced me into an iphone, and I've had it about 2 weeks. The things I miss the most are a notification light and my calendar/To-do on the home screen. The battery life has been tough on the iphone, and I prefer the size of the Nokia, but the iphone is still a very nice device. I'm about to put the sim back in the Nokia and put the 3GS back in the box.

In the past year I've gone this route:
-HTC Touch Pro (buggy, needed rebooting at least once a day, battery life made the iPhone seem like it lasts forever!)
-Blackberry Curve (great phone, outdated though)
-HTC Hero (not bad, not great though)
-Blackberry Curve 2 (didn't like the cheap feel)
-Blackberry Tour (great phone, again outdated - RIM needs to step it up!)

While using my Tour, I bought an Ipod Touch on a sunday. On monday I was calling AT&T to inquire about an iPhone and plans! While there are several things that boggle my mind that the iPhone CAN'T do (without jailbreaking) like SMS ringtones, multitask, LED notification light, etc. - it really is a great phone.

I used to be a HUGE Blackberry fan and an even BIGGER iPhone hater. I started out with the little pearl 8100, and then moved over to the curve 8310. I bought an unlocked 9500 from England and used that for awhile and then went to the Bold 9000 and a Curve 8900 at the same time. I finally broke down and got the iPhone after listening to the radio and hearing the DJ say that the iPhone was the greatest thing to hit the market since steak and potatoes!! I bought the 3GS and fell in love with it immediately. Thanks Steve!!